It's hard because Nintendo systems are mostly all great but my ranking would probably look like this -
SNES - the point when 2D gaming was refined and perfected, and many games released in the 16bit era have yet to be topped. None of the greats on that system show their age, except perhaps Starfox and Donkey Kong Country
3DS - Only reason this ranks above DS is because Nintendo's own offerings have been fantastic so far
DS - Hit and miss first party, but some of my favourite games were on this system
Wii - Super Mario Galaxy 2 is pretty good
Wii U - Many of this system's games manage to be debatably the best in their genres, like Tropical Freeze and Bayonetta 2, and Nintendo's output is on point with two top tier Mario platformers and a Mariokart I didn't ditch a week after buying it, but it's a real shame that games on the system are so far in between each other
GBA - Similar case to the DS. Hit and miss Nintendo output consisting largely of inferior SNES ports and no original Mario platformer but some incredible third party games and interesting takes on existing franchises
Gamecube - I wish that obviously fake TTYD leak was real so I could see why people think this system is any more worthwhile than the Wii U
NES - Saved the industry so well done with that one
N64 - Mario 64 and OoT are great and most likely shaped the current gaming landscape, but other than that this is just a messy system that perfectly emphasises the growing pains of the industry when things went 3D. I don't really consider this as a system I enjoy playing on as much as I consider it laying the foundations for better things to come
Gameboy - I'm not a dog, Nintendo. How dare you not even give me games in colour. Disgusting.